The present invention claims the benefit of Korean Patent Application No. 89294/2001 filed in Korea on Dec. 31, 2001, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a method and apparatus for forming a pattern, and particularly, to a method and apparatus for forming a pattern capable of simplifying the fabrication process improving productivity when a liquid crystal display device is fabricated by a printing method.
2. Discussion of the Related Art
In general, a cathode-ray tube (CRT) monitor has been mainly used for displaying information in a TV and a computer. The CRT has a high image quality and high screen brightness, and thereby the CRT has been the main stream of the display devices. However, as the screen size is increased, the size and weight of the CRT monitor is greatly increased occupying a large space, and becoming impractical as a portable device.
Flat panel display devices, such as a liquid crystal display (LCD), plasma display panel (PDP), organic electro luminescence (EL), light emitting diode (LED) and field emission display (FED), have been developed for solving the above problems. Among these flat panel display devices, the LCD is highlighted since it has been widely used in notebook PC""s or computer monitors, and it has low power consumption.
FIG. 1 is a cross-sectional view of a liquid crystal display device according to the related art. As shown in FIG. 1, the LCD device comprises an upper substrate 10, a lower substrate 20 and a liquid crystal layer 30 formed therebetween. A color filter 11, which generates colored light, comprising a black matrix 12 for preventing light leaking between pixels and a resin layer including dyes or pigments of red, green, and blue colors, and are formed on the upper substrate 10. In addition, an over coat layer (not shown) may be formed on the color filter 11 for flattening the color filter 11 and improving bonding with an ITO, and a common electrode 13, which is a transparent conductive material for applying a voltage to the liquid crystal layer 30, are formed on upper part thereof. In addition, an alignment layer 14a for aligning liquid crystal molecules is formed on the common electrode 13.
A thin film transistor (T) and a pixel electrode 21, which is an electrode corresponding to the common electrode 13, are formed on the lower substrate 20. The thin film transistor (T) comprises a gate electrode 15 to which a scan signal is applied, an active layer 16 for transmitting data signals corresponding to the scan signal, a gate insulating layer 17 for electrically isolating the active layer 16 and the gate electrode 15, a source electrode 18a formed on an upper part of the active layer 16 for applying a data signal, and a drain electrode 18b for applying the data signal to a pixel electrode 21. The active layer 16 comprises a semiconductor layer 16a formed by depositing amorphous silicon (a-Si), and an ohmic contact layer 16b n+-doped on both upper sides of the semiconductor layer 16a. 
A passivation layer 19 for exposing a part of the drain electrode 18b is formed on the thin film transistor (T), and the pixel electrode 21 and the drain electrode 18b are electrically connected through the exposing portion. In addition, the pixel electrode 21 and the common electrode 13 are formed as transparent electrodes made of an ITO so that light can be transmitted, and a second alignment layer 14b for aligning the liquid crystal molecules is formed on an upper part of the pixel electrode 21.
In order to fabricate the liquid crystal display device discussed above, a plurality of thin film deposition processes, photolithography processes and etching processes should be repeated. In order to fabricate the thin film transistor (T), the color filter 11, and the black matrix 12, a photoresist pattern is formed by an exposure process using a photoresist or a mask, and an etching process is performed thereafter. However, the above processes for forming the photoresist pattern are complex, and cost for fabricating the mask is increased as the substrate is increased. Therefore, a printing method by which the patterned resist can be formed without the exposing process has been recently suggested.
FIGS. 2A through 2D are cross sectional views of a method and apparatus for forming a pattern using a gravure offset printing method according to the related art. As shown in FIG. 2A, resist is applied onto a clichxc3xa9 24 on which a recess 23 is formed, thereafter, a doctor blade 32 flattens the clichxc3xa9 on which the resist is applied. At that time, the resist 31 is formed in the recess 23, and any other resist remaining on the area is removed.
As shown in FIG. 2B, a roller 33 is rotated contacting the clichxc3xa9 24, and the resist 31 filled in the recess 23 of the clichxc3xa9 24 is transferred onto the roller 33.
As shown in FIG. 2C, a substrate 10a on which a pattern will be formed is loaded on a lower part of the roller 33, and the roller 33 is rotated to re-transfer the resist 31a onto the substrate 10a. 
FIG. 2D shows the resist pattern 31a formed on the substrate 10a through the above gravure offset printing process.
FIG. 3 is a planar view of a gravure offset printing apparatus according to the related art. As shown in FIG. 3, in the gravure offset printing apparatus, the clichxc3xa9 24, on which the concave recess 23 is formed, and a stage 25, on which the substrate 10a for forming the pattern is disposed, are integrally constructed. The roller 33 is provided for transferring the resist pattern onto the substrate 10a from the clichxc3xa9 24. The roller 33 can be rotated and reciprocated between the clichxc3xa9 24 and the stage 25, and the roller 33 stained with the resist filled in the clichxc3xa9 24 transfers the resist pattern onto the substrate in one rotation.
FIG. 4 is a cross-sectional view of the gravure printing apparatus taken along I-Ixe2x80x2 of FIG. 3. The clichxc3xa9 24, on which the recess 23 is formed, and the stage 25 are integrally formed, and the roller 33 located on an upper part of the clichxc3xa9 24 moves between the clichxc3xa9 24 and the stage 25 to form the resist pattern on the substrate 10a. In order to re-transfer the resist transferred from the clichxc3xa9 24 onto the substrate 10a in one try, a width of the roller 33 should be the same or more as that of the substrate. Therefore, the size of the roller increases as the size of the liquid crystal panel is increased, and thereby cost for fabricating the roller is increased. When the resist is transferred onto the roller 33 from the clichxc3xa9, the resist is not smoothly separated from the recess of the clichxc3xa9. Therefore, some resist remains in the recess, and the surface of the resist transferred to the roller is not flat. Thereby, a gap between the substrate and the resist is formed when the resist is re-transferred onto the substrate. When the substrate is etched in the etching process, etchant flows into the gap and the part is etched unnecessarily. Therefore, a fatal error may occur in the display device which requires a pattern of high precision. Also, the resist remaining on the roller should be cleaned regularly.
Accordingly, the present invention is directed to a method and apparatus for forming a pattern using a printing method that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide simplified fabrication processes and a printing apparatus for transferring a resist pattern onto a substrate after attaching the substrate on a clichxc3xa9 without a roller.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method for forming a pattern including the steps forming a recess on a clichxc3xa9 corresponding to a position of a pattern, filling one of resist and ink within the recess of the clichxc3xa9, affixing a substrate on which the pattern is to be formed on a loading plate, aligning the loading plate on the clichxc3xa9, attaching the substrate to the clichxc3xa9, and separating the substrate from the clichxc3xa9.
In another aspect of the invention, there is provided a method for forming a pattern including the steps of forming a recess on a clichxc3xa9 corresponding to a position of a pattern to be formed, filling one of resist and ink within the recess of the clichxc3xa9 using a doctor blade, affixing a substrate on which the pattern will be formed on a loading plate, aligning the loading plate on the clichxc3xa9, attaching the substrate to the clichxc3xa9, and setting a temperature of the loading plate to be higher than a temperature of the clichxc3xa9, separating the loading plate from the clichxc3xa9, and separating the substrate from the loading plate.
In another aspect of the invention there is provided an apparatus for forming a pattern including a clichxc3xa9 having at least one recess for forming a pattern, a loading plate including a vacuum chuck and a heater, and a substrate.
It is to be understood that both the foregoing general description and the following detailed description, are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.